Respuesta :
We need to use formula a² -b² = (a-b)(a+b),
and here we need to use this formula 2 times.
n⁴ -1 = (n²)² -1² =(n² -1)(n²+1) = (n² -1²)(n²+1) = (n²+1)(n-1)(n+1)
and here we need to use this formula 2 times.
n⁴ -1 = (n²)² -1² =(n² -1)(n²+1) = (n² -1²)(n²+1) = (n²+1)(n-1)(n+1)
